Thanks for joining in the thread, @Noel123.
I can help show you how to create an account for custom duty mentioned by @Rustler. However, I'd suggest consulting the advice or your accountant in choosing the account that's best for your business.
Here's how to create a custom duty account:
Then let's follow the rest of the steps of the workaround given by @Rustler.
As always you can contact our Online Care Support if you need assistance in going through the steps. They can pull up your account and do a screen sharing to help you with the navigation in QuickBooks.
Please feel free to post if you need anything else. Have a good one.